Under a blazer, you wear a shirt for a formal or business look. A knitted polo is slightly less formal. In autumn and winter, a fine knit with a quarter zip or crew neck also works. In general, a smooth, light base layer looks more formal than a layer with more texture. Above all, the base layer must be thin enough to let the blazer sit well. Below you can read when and how to wear each option.
The three main options side by side
| Base layer | Look | Suitable for | Watch out for |
|---|---|---|---|
| Shirt | Formal to business | Office, presentations, dinners, weddings | Collar firm enough, sleeves just visible |
| Knitted polo | Neat and relaxed | Office without a tie, drinks, dinners | Keep the collar inside the lapels |
| Fine knit (quarter zip or crew neck) | Modern and warm | Autumn and winter, travel, creative offices | Thin enough, not a thick sweater |
| T-shirt | Casual | Weekend, informal evenings | Only with an unlined, soft blazer |
The shirt: the classic
A shirt is the most formal choice under a blazer. Pay attention to three things. The collar must be firm enough to stand up, even without a tie. The sleeves should come out about a centimetre below the sleeve of the blazer. And the fit must be slim enough not to form folds under the jacket.
A shirt with an Italian collar is ideal if you do not wear a tie: the collar spreads a little wider and lies nicely on the lapels. The Hamilton shirt in light blue, made of 100% cotton, is a calm choice for the office that works with both a navy and a grey blazer. Light blue is slightly softer than white and flatters most skin tones.
The knitted polo: neat without a tie
A knitted polo is a neat alternative to a shirt. The collar keeps the outfit neat, while the knit looks softer and less formal. Important: choose a knitted polo and not a sporty jersey piqué. A knitted polo drapes more softly and has a collar that keeps its shape well.
The Trenton in black, an open polo made of 100% merino wool, is a strong example. Merino wool keeps you warm in autumn, breathes well and stays fresh for longer naturally, which is handy on a long day in a blazer. Read more about the material on our merino wool page. For a lighter look, the Alistair in cream, a knitted piqué polo with stripe detail, looks wonderful under a dark blazer. The light colour against the dark jacket gives contrast without becoming too formal.
An open polo without buttons, such as the Theodore in light blue, gives a calm line under a blazer.
Always keep the collar of the polo inside the lapels of the blazer. A polo collar that lies over the lapels looks untidy and recalls the seventies.
The fine knit: warmth without bulk
When it gets colder, a fine-knit layer with a quarter zip or crew neck is an elegant choice. The Edmund in light grey melange, a fine-knit polo with quarter zip in lyocell, is thin enough to fit under a blazer without the shoulders pulling. You can wear the zip open if it is warm indoors, or closed under a coat.
With knitwear under a blazer, thickness is what matters most. A chunky sweater makes the blazer too tight and distorts the shoulder line. So always choose fine knit, and check in the mirror that the lapels still lie flat.
Combining colours
A blazer and base layer in the same colour family make a calm combination: a navy blazer with a light blue shirt, a grey blazer with a light grey knit, a brown blazer with a cream polo. If you want contrast, choose a dark blazer with a light base layer or the other way round. Avoid two different strong colours; let one of the two be neutral.
The trousers play a part too. Slim-fit herringbone trousers such as the Ulysses in taupe grey suit a plain blazer and a calm base layer. With a patterned blazer, choose plain trousers.
Four outfits for the autumn
- Office with clients: navy blazer, light blue shirt with Italian collar, grey trousers, brown leather shoes.
- Office without a tie: grey blazer, black merino polo, black trousers, loafers.
- Dinner in town: dark brown or navy blazer, cream knitted polo, taupe herringbone trousers, suede loafers.
- Travel day or cold morning: soft unlined blazer, light grey knit with quarter zip, dark trousers, smart sneakers.
From autumn to winter
Adapt the base layer to the season. In early autumn, a shirt or a light knitted lyocell polo is enough under a cotton blazer or a light wool blend. When it gets colder in November, switch to merino wool or a fine knit with a quarter zip, and the blazer itself can be heavier: flannel, tweed or a dense wool. In winter you can even wear two thin layers under a blazer, such as a shirt with a fine-knit sweater over it, as long as the jacket does not pull. An overcoat goes over all of it; choose one with enough room in the shoulders, so blazer and base layer are not squashed. If you take your blazer off on the train or in the car, hang it over a chair or on a hook with the shoulders well supported, so it sits neatly again on arrival.
Common mistakes
- A base layer that comes out below the blazer at the bottom. Your shirt or polo should not be longer than the jacket.
- A T-shirt with a stretched neck under a formal blazer.
- A shirt with a limp collar and no tie; it sinks away under the lapels.
- A polo with the collar turned up or lying over the lapels.
For more combinations, take a look at our shirts, the knitwear for men or the Office for Men collection.
Shop the look
Hamilton: shirt with Italian collar, light blue
Trenton: open merino wool polo, black
Alistair: knitted piqué polo, cream
Theodore: fine-knit open polo in lyocell, light blue
Edmund: polo with quarter zip in lyocell, light grey melange
Ulysses: slim-fit herringbone trousers, taupe grey
Frequently asked questions
Can I wear a polo under a blazer at the office?
Yes, a knitted polo is a neat alternative to a shirt in most offices. Choose a fine-knit polo with a collar that stays neatly inside the lapels.
Should the polo collar go over or under the lapels?
Under or inside the lapels. A collar that lies over the blazer looks old-fashioned and untidy.
Which sweater goes under a blazer?
A fine-knit sweater or polo with a quarter zip or crew neck. A chunky sweater makes the blazer too tight and distorts the shoulders.
